TWI547014B - Planar dual polarization antenna and complex antenna - Google Patents

Description

Flat dual-polarized antenna and composite antenna

The invention relates to a flat-plate dual-polarized antenna and a composite antenna, in particular to a wide frequency band, a wide beam, a high antenna gain, a high co-polarization pair orthogonal polarization (Co/Cx) value, a small antenna size and A flat-plate dual-polarized antenna and a composite antenna are generated which are inclined at a 45-degree orthogonal dual-polarized antenna field.

Electronic products with wireless communication functions, such as a notebook computer, a personal digital assistant, etc., transmit or receive radio waves through an antenna to transmit or exchange radio signals to access a wireless network. Therefore, in order to make it easier for users to access the wireless communication network, the bandwidth of the ideal antenna should be increased as much as possible within the allowable range, and the size should be minimized to match the trend of shrinking electronic products. In addition, as wireless communication technologies continue to evolve, the number of antennas configured for electronic products may increase. For example, the Long Term Evolution (LTE) wireless communication system supports Multi-input Multi-output (MIMO) communication technology, that is, related electronic products can be synchronously transmitted and received through multiple (or multiple groups of) antennas. Wireless signal to greatly increase the system's data throughput (Throughput) and transmission distance without increasing the bandwidth or total transmission power loss (Transmit Power Expenditure), thereby effectively improving the spectrum efficiency and transmission rate of the wireless communication system. Improve communication quality. In addition, multi-input and multi-output communication technology can be combined with spatial multiplexing, beam forming, spatial diversity, and precoding to further reduce signal interference and increase channel capacity.

In addition, the long-term evolution wireless communication system uses a total of 44 frequency bands, covering frequencies from the lowest 698MHz to the highest 3800MHz. Due to the dispersion and clutter of frequency bands, system operators may use multiple frequency bands simultaneously, even in the same country or region. In this case, how to design conformity The transmission of the required antenna, while taking into account the size and function, has become one of the goals of the industry.

Therefore, the present invention mainly provides a flat-panel dual-polarized antenna to solve the disadvantage that the conventional antenna beam width is narrow.

The present invention discloses a flat-panel dual-polarized antenna for transmitting and receiving at least one radio signal, comprising a first microstrip metal piece; a grounded metal plate comprising a first pattern slot and a second pattern slot, wherein the One of the first pattern slots is formed by a first rectangle and a second rectangle separated by an angle, the first rectangle and the second rectangle coincide with a vertex, and the first pattern slot and the second The pattern slots are mutually symmetric with respect to a central axis of the first microstrip metal sheet; and a first dielectric layer is formed between the first microstrip metal sheet and the grounded metal plate.

The invention further discloses a composite antenna for transmitting and receiving at least one radio signal, comprising a first planar dual-polarized antenna layer, comprising a plurality of first microstrip metal sheets; and a grounded metal plate comprising a plurality of rectangular blocks Each of the rectangular blocks is disposed corresponding to the first microstrip metal piece of the plurality of first microstrip metal pieces, and each of the rectangular blocks includes a first pattern slot and a second pattern slot, wherein the One of the pattern slots is formed by a first rectangle and a second rectangle separated by an angle, the first rectangle and the second rectangle coincide with a vertex, and the first pattern slot and the second pattern The slots are mutually symmetrical with respect to a central axis of the corresponding first microstrip metal sheet; and a first dielectric layer is formed between the first flat dual polarized antenna layer and the grounded metal plate.

10‧‧‧Single dual polarized antenna

20‧‧‧ Back to the shape of the dart

30, 40, 61~66, 70‧‧‧ composite antenna

100, 300‧‧‧Feed into the transmission line layer

102a, 102b, FTL_1a, FTL_1b, FTL_2a, FTL_2b‧‧‧ feed transmission line

110, 130, 150, 310, 330, 350‧‧‧ dielectric layers

120, 320, 420, 720‧‧‧ grounded metal plates

122a, 122b, SL_1a, SL_1b, SL_2a, SL_2b‧‧‧ slots

124a, 124b, PSL_1a, PSL_1b, PSL_2a, PSL_2b, PSL_5a, PSL_5b, PSL_6a, PSL_6b‧‧‧ pattern slot

140, 160, UPP_1, UPP_2, DPP_1, DPP_2‧‧‧ microstrip metal sheets

200a, 200b, 210a, 210b‧‧‧ rectangle

340, 360‧‧‧ flat dual-polarized antenna layer

L‧‧‧ total length

L1, L7‧‧‧ length

W1, W7‧‧‧ width

L2‧‧‧Bianchang

W2‧‧‧ side width

Axis_y‧‧‧ axis of symmetry

P1‧‧‧ apex

Θ1, θ2‧‧‧ angle

SC1, SC2, SC3, SC4, SC5, SC6‧‧‧ rectangular blocks

CL_1, CL_2‧‧‧ central axis

D‧‧‧Distance

FIG. 1A is a top view of a flat dual-polarized antenna according to an embodiment of the present invention.

Fig. 1B is a schematic cross-sectional view of the flat double-polarized antenna taken along line A-A' of Fig. 1A.

FIG. 2 is a schematic view showing the shape of a back-dart according to an embodiment of the present invention.

FIG. 3 is a top view of a composite antenna according to an embodiment of the present invention.

4A is a top view of a composite antenna according to an embodiment of the present invention.

Fig. 4B is a schematic isometric view of the composite antenna shown in Fig. 4A.

Fig. 5A is a schematic diagram showing the result of antenna resonance simulation of the composite antenna shown in Fig. 4A.

Fig. 5B~5E is a schematic diagram showing the simulation results of the antenna field characteristics of the composite antenna shown in Fig. 4A.

FIG. 6A is a top view of a composite antenna according to an embodiment of the present invention.

FIG. 6B is a top view of a composite antenna according to an embodiment of the present invention.

FIG. 6C is a top view of a composite antenna according to an embodiment of the present invention.

FIG. 6D is a top view of a composite antenna according to an embodiment of the present invention.

FIG. 6E is a top view of a composite antenna according to an embodiment of the present invention.

FIG. 6F is a top view of a composite antenna according to an embodiment of the present invention.

FIG. 7 is a top view of a composite antenna according to an embodiment of the present invention.

Please refer to FIG. 1A and FIG. 1B. FIG. 1A is a top view of a flat dual-polarized antenna 10 according to an embodiment of the present invention, and FIG. 1B is a cross-sectional line A-A' of the flat dual-polarized antenna 10 along the first FIG. Schematic diagram of the section. The flat-panel dual-polarized antenna 10 can be used to transmit and receive radio signals in broadband or multiple frequency bands, such as the signals of Band 40 and 41 in the long-term evolution wireless communication system (the frequency band is roughly between 2.3 GHz and 2.4 GHz and 2.496 GHz to 2.690 GHz). As shown in FIGS. 1A and 1B, the planar dual-polarized antenna 10 is substantially a seven-layer structure and has an axisymmetric structure with respect to the axis of symmetry axis_y, and includes a feed transmission line layer 100, dielectric layers 110, 130, 150, and a grounded metal. Plate 120 and microstrip metal sheets 140, 160. The microstrip sheet metal 140 is the primary radiator and is generally shaped like a cross to create linear polarization and to avoid the generation of circularly polarized electromagnetic waves. The microstrip metal sheet 160 serves to increase the bandwidth of the antenna resonance and is not in direct contact with the microstrip metal sheet 140 by the dielectric layer 150. Preferably, the center of the microstrip metal piece 140 is aligned with the center of the microstrip metal piece 160 to a central axis CL_1 of the microstrip metal piece 140, and the central axis CL_1 is disposed perpendicular to the axis of symmetry axis_y. The feed transmission line layer 100 includes feed transmission lines 102a, 102b that are symmetric about the axis of symmetry axis_y and orthogonal to each other to feed two types of radio signals (e.g., different polarization directions). The grounded metal plate 120 is used to provide grounding and includes slots 122a, 122b and pattern slots 124a, 124b. Slots 122a, 122b are respectively fed Transmission lines 102a, 102b are orthogonal and symmetrical about the axis of symmetry axis_y to produce an orthogonal dual-polarized antenna pattern.

In short, the length L1 of the grounded metal plate 120 along the axis of symmetry axis_y is greater than the width W1 of the grounded metal plate 120 in the x direction, so that the beam width (3dB beamwidth) can be increased. Also, the pattern slots 124a, 124b of the grounded metal plate 120 can balance the asymmetry of the length L1 and the width W1 to improve the co-polarization versus orthogonal polarization (Co/Cx) values.

In detail, in order to increase the beam width in the horizontal section (xz plane), it is necessary to shorten the width W1 of the grounded metal plate 120 in the x direction so that the radiation field shape in the horizontal direction is more divergent, and therefore, the plate double polarization is appropriately designed. After the antenna 10, the length L1 of the grounded metal plate 120 along the axis of symmetry axis_y is greater than the width W1 of the grounded metal plate 120 in the x direction. Since the length L1 and the width W1 are not equal, the resonance lengths of the vertical direction and the horizontal direction are different, so that the asymmetry caused by the length L1 being larger than the width W1 can be balanced by the pattern slots 124a and 124b. Wherein, the pattern slots 124a, 124b generally have a Boomerang shape 20. Please refer to FIG. 2, which is a schematic view of the shape of the back-dart body 20 according to an embodiment of the present invention. The bounce shape 20 is composed of rectangles 210a and 210b having the same shape and size, and the rectangles 210a and 210b have one apex P1. Further, the rectangles 210a and 210b can be regarded as the original side-by-side rectangles 200a and 200b formed by the apex P1 being a rotation fulcrum and rotating outward from the axis of symmetry axis_y by angles θ 1 and θ 2 , respectively. Preferably, the angles θ 1 and θ 2 are 20°, but are not limited thereto. As shown in FIGS. 1A and 2, the bounce shape 20 is symmetrical with respect to the axis of symmetry axis_y, and the pattern slots 124a, 124b are symmetrical with respect to the central axis CL_1 of the microstrip sheet metal 140. In addition, since the dielectric layers 110, 130 isolate the feed transmission line layer 100, the ground metal plate 120, and the planar dual polarized antenna layer 140 from each other, the radio signal is coupled to the slot by a feed transmission line (eg, 102a) (eg, 122a). And resonating through the slots (e.g., 122a) and coupling to the microstrip metal sheet 140 to increase the antenna bandwidth. Moreover, the resonance direction of the cruciform microstrip metal piece 140 is inclined with respect to the grounded metal plate 120 to effectively reduce the size of the antenna and at the same time meet the requirement of polarization tilt of 45 degrees.

It should be noted that the flat dual-polarized antenna 10 of FIGS. 1A and 1B is the embodiment of the present invention. The embodiments are generally modified by those skilled in the art and are not limited thereto. For example, to increase the antenna gain, the planar dual-polarized antenna 10 can be further utilized to form an array antenna. Please refer to FIG. 3, which is a top view of a composite antenna 30 according to an embodiment of the present invention. Similar to the flat dual-polarized antenna 10, the composite antenna 30 also has a substantially seven-layer architecture, including a feed transmission line layer 300, three dielectric layers (not shown), a grounded metal plate 320, and a planar dual-polarized antenna layer 340. 360. The difference is that the planar dual-polarized antenna layer 340 includes cross-shaped microstrip metal sheets DPP_1, DPP_2. The feed transmission lines FTL_1a, FTL__1b, FTL_2a, and FTL_2b fed to the transmission line layer 300 are respectively disposed corresponding to the microstrip metal pieces DPP_1, DPP_2 to feed the (two polarized) radio signals. The microstrip metal sheets UPP_1 and UPP_2 of the planar dual-polarized antenna layer 360 are also respectively disposed corresponding to the microstrip metal sheets DPP_1 and DPP_2, and the grounded metal plate 320 can be divided into rectangular blocks SC1 and SC2, and the rectangular blocks SC1 and SC2 are disposed. The slots SL_1a, SL_1b, and SL_2a, SL_2b are respectively provided corresponding to the feed transmission lines FTL_1a, FTL_1b, FTL_2a, and FTL_2b.

In detail, since the base station of the long term evolution wireless communication system is located substantially near the earth's surface, and based on the distance between the base station and the receiver, the radiant energy of the composite antenna 30 should preferably be concentrated in the relative horizontal line in the vertical section (yz plane). (z-axis) is within the range of plus or minus 10 degrees of elevation, so the 1x2 array antenna can be formed by vertically arranging the microstrip metal sheets DPP_1, DPP_2 up and down to achieve the antenna gain value required by the system. Further, by making the length L1 of the rectangular blocks SC1, SC2 along the axis of symmetry axis_y larger than the width W1 of the rectangular blocks SC1, SC2 in the x direction, the beam width in the horizontal slice (xz plane) can be increased. Table 1 is an antenna characteristic table of the composite antenna 30. As can be seen from Table 1, the composite antenna 30 can still substantially meet the requirements of the long-term evolution wireless communication system for the maximum gain value and the front-rear field ratio (F/B), and when the ground metal is When the width W1 of the plate 320 is reduced from 100 mm to 70 mm, the beam width in the horizontal direction can be increased to 69.5°-73.0°.

In order to further increase the co-polarization versus the discontinuous polarization (Co/Cx) value of the composite antenna 30, the structure of the grounded metal plate 320 can be appropriately adjusted. Please refer to FIG. 4A and FIG. 4B. FIG. 4A is a top view of the composite antenna 40 according to the embodiment of the present invention, and FIG. 4B is a schematic view of the composite antenna 40. The composite antenna 40 includes a feed transmission line layer 300, dielectric layers 310, 330, 350, a grounded metal plate 420, and planar dual polarized antenna layers 340, 360. In other words, the structure of the composite antenna 40 is substantially similar to that of the composite antenna 30, so the same components are denoted by the same reference numerals for simplicity. The difference is that the rectangular blocks SC3 and SC4 of the grounded metal plate 420 further include patterned slots PSL_1a, PSL_1b, and PSL_2a, PSL_2b, respectively, to balance the asymmetry of the length L1 greater than the width W1. The pattern slots PSL_1a, PSL_1b, and PSL_2a, PSL_2b respectively have the bounce shape 20 shown in FIG. 2, and are respectively symmetrical with respect to the central axes CL_1 and CL_2 of the microstrip metal sheets DPP_1 and DPP_2.

In other words, the composite antenna 40 can increase the antenna gain value by the array antenna structure and increase the beam width by shortening the width W1 of the rectangular blocks SC3, SC4. In order to balance the asymmetry between the length L1 and the width W1, the rectangular blocks SC3 and SC4 respectively include pattern slots PSL_1a, PSL_1b and PSL_2a, PSL_2b to improve the co-polarization versus orthogonal polarization (Co/Cx) values. .

Through the simulation and measurement, it can be further judged whether the composite antenna 40 meets the system requirements. In detail, please refer to Figure 5A. FIG. 5A is a schematic diagram of the antenna resonance simulation result of the composite antenna 40, wherein the dotted line represents the antenna resonance simulation result of the 45 degree polarization tilt of the composite antenna 40, and the solid line represents the antenna resonance simulation of the 135 degree polarization tilt of the composite antenna 40. As a result, the broken line represents the simulation result of the antenna isolation of the 45-degree polarization tilt and the 135-degree polarization tilt of the composite antenna 40. Like 5A As shown, the composite antenna 40 has a 45-degree polarization tilt of the Band 40 and 41 and a return loss (S11 value) of the 135-degree polarization tilt antenna below -11.8 dB, and a 45-degree polarization tilt and a 135-degree pole. The isolation between the tilts is at least 22.5dB. In addition, Table 2 is an antenna characteristic table of the composite antenna 40, and FIGS. 5B-5E are antenna field characteristics of the composite antenna 40 applied to the long-term evolution wireless communication system and operating at 2.3 GHz, 2.4 GHz, 2.496 GHz, and 2.69 GHz, respectively. A schematic diagram of the simulation results, wherein the solid line represents the radiation pattern of the same polarization of the composite antenna 40 in the horizontal section (Phi = 0 degree angle), and the dotted line represents the same polarization of the composite antenna 40 in the vertical section (Phi = 90 degree angle) The radiation field type, the long dashed line represents the radiation pattern of the orthogonal polarization of the composite antenna 40 in the horizontal section (Phi = 0 degree angle), and the short dashed line represents the orthogonal polarization of the composite antenna 40 in the vertical section (Phi=90) Radiation pattern of degree angle). As can be seen from Table 2 and Figures 5B to 5E, the composite antenna 40 not only has a wide beam width in the horizontal direction, but also satisfies the requirements of the long-term evolution wireless communication system for the maximum gain value and the front-rear field ratio (F/B). And the co-polarization versus orthogonal polarization (Co/Cx) value is at least greater than 16.3 dB.

It should be noted that the flat dual-polarized antenna 10 and the composite antennas 30, 40 are embodiments of the present invention, and those skilled in the art can make different changes. For example, the segmentation bending conditions of the feed transmission lines 102a, 102b, FTL_1a, FTL_1b, FTL_2a, FTL_2b and the slots 122a, 122b, SL_1a, SL_1b, SL_2a, SL_2b may be appropriately changed according to different design considerations, such as adjusting the angle. Form an obtuse or acute angle, or adjust the length proportional relationship between the segments and the width ratio relationship, or adjust the shape of the segment and the number of segment segments. In addition, "substantially cross-shaped" means The appearance of the microstrip metal sheets 140, 160, UPP_1, UPP_2, DPP_1, DPP_2 is composed of two rectangular microstrip metal sheets overlapping and staggered, but is not limited thereto. For example, the microstrip metal sheet may extend out of the square side plate. The serrated side plate or the curved side plate, or the edge of the microstrip metal piece is arc-shaped. The dielectric layers 110, 130, 150, 310, 330, 350 can be various electrical isolation materials, such as air, and the microstrip metal sheet 160, the flat dual polarized antenna layer 360, and the dielectric layers 150, 350 can be video wide. Selective settings. Further, the composite antennas 30 and 40 are 1×2 array antennas, but are not limited thereto, and may be 1×3, 2×4 or mxn array antennas.

On the other hand, the side length L2 of the rectangle 200a of the bounce back shape 20 shown in Figs. 2, 4A, and 4B is 25 mm, the side width W2 is 2.5 mm, and the apex P1 of the back dart shape 20 is from the central axis (e.g., CL_1 or CL_2). The distance D is 47.449 mm, but the invention is not limited thereto, and can be appropriately adjusted according to different system requirements. For example, please refer to FIG. 6A to FIG. 6F and Table 3. FIG. 6A to FIG. 6F are schematic diagrams of the composite antennas 61-66 according to the embodiment of the present invention, and Table 3 is an antenna characteristic table of the composite antennas 61-66. As shown in Table 3, the antenna characteristics can be adjusted by appropriately adjusting the size of the pattern slots of the composite antennas 61-66, wherein the co-polarization versus orthogonal polarization (Co/Cx) values are greater than 15.8 dB.

In addition, if the beam width in the horizontal slice (xz plane) is to be reduced, the width of the grounded metal plate in the x direction can be lengthened. Please refer to FIG. 7. FIG. 7 is a top view of a composite antenna 70 according to an embodiment of the present invention. The structure of the composite antenna 70 is substantially similar to that of the composite antenna 40, so the same components are denoted by the same symbols for the sake of brevity. The difference is that the width W7 of the grounded metal plate 720 along the x direction is appropriately designed to be lengthened so that the radiation field shape in the horizontal direction is more concentrated. Therefore, the rectangular blocks SC5 and SC6 of the grounded metal plate 720 are along the axis of symmetry axis_y. The length L7 is smaller than the width W7 of the rectangular blocks SC5 and SC6 in the x direction. Further, the rectangular blocks SC5 and SC6 of the grounded metal plate 720 further include patterned slots PSL_5a, PSL_5b, and PSL_6a, PSL_6b, respectively, so that the balance length L7 is smaller than the width W7.

In summary, the present invention adjusts the block of the microstrip metal piece corresponding to the grounded metal plate. Length to width ratio to increase beam width. Moreover, the grounded metal plate includes patterned slots to balance the asymmetry caused by the difference in length and width of the block, and to ensure the co-polarization versus orthogonal polarization (Co/Cx) value.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

10‧‧‧Single dual polarized antenna

100‧‧‧Feed into the transmission line layer

102a, 102b‧‧‧Feed into the transmission line

120‧‧‧Grounded metal plate

122a, 122b‧‧‧ slots

124a, 124b‧‧‧ pattern slots

140, 160‧‧‧Microstrip metal sheet

L1‧‧‧ length

W1‧‧‧Width

Axis_y‧‧‧ axis of symmetry

P1‧‧‧ apex

CL_1‧‧‧ center axis

D‧‧‧Distance

Claims (14)

A flat-panel dual-polarized antenna for transmitting and receiving at least one radio signal, comprising: a first microstrip metal piece; a grounded metal plate comprising a first pattern slot and a second pattern slot, wherein the One of the pattern slots is formed by a first rectangle and a second rectangle separated by an angle, the first rectangle and the second rectangle coincide with a vertex, and the first pattern slot and the second pattern The slots are mutually symmetrical with respect to a central axis of the first microstrip metal sheet; and a first dielectric layer is formed between the first microstrip metal sheet and the grounded metal plate. The flat-panel dual-polarized antenna according to claim 1, wherein the length of one of the grounded metal plates along one of the axes of symmetry is not equal to the width of one of the grounded metal plates to adjust the beam width, and the axis of symmetry is perpendicular to the center. axis. The flat-panel dual-polarized antenna of claim 2, wherein the first pattern slot and the second pattern slot are respectively symmetric with respect to the axis of symmetry. The flat-panel dual-polarized antenna according to claim 1, wherein the first microstrip metal piece has a shape of a cross. The flat dual-polarized antenna of claim 2, further comprising: a feed transmission line layer, including a first feed transmission line and a second feed transmission line, the first feed transmission line and the second feed The transmission line is symmetrical to the axis of symmetry; and a second dielectric layer is formed between the feed transmission line layer and the grounded metal plate. The flat-panel dual-polarized antenna of claim 5, wherein the grounded metal plate comprises a first slot and a second slot, the first slot and the second slot being symmetric with the axis of symmetry, the first A slot is coupled to the first feed transmission line, and the second slot is coupled to the second feed transmission line to increase the bandwidth of the planar dual polarization antenna. The flat dual-polarized antenna according to claim 1 further comprising a second microstrip metal sheet formed And over the first microstrip metal sheet, and not contacting the first microstrip metal sheet. A composite antenna for transmitting and receiving at least one radio signal includes: a first flat dual-polarized antenna layer including a plurality of first microstrip metal sheets; and a grounded metal plate including a plurality of rectangular blocks, each A rectangular block is disposed corresponding to the first microstrip metal piece of the plurality of first microstrip metal pieces, each rectangular block includes a first pattern slot and a second pattern slot, wherein the first pattern One of the slots is formed by a first rectangle and a second rectangle separated by an angle, the first rectangle and the second rectangle are coincident with a vertex, and the first pattern slot and the second pattern slot And a first dielectric layer is formed between the first planar dual polarized antenna layer and the grounded metal plate. The composite antenna according to claim 8, wherein each of the rectangular blocks has a length unequal to one of the rectangular blocks along a length of the symmetry axis to adjust the beam width, and the symmetry axis is perpendicular to the rectangular block. Corresponding to the central axis of the first microstrip metal piece. The composite antenna according to claim 8, wherein the plurality of first pattern slots and the plurality of second pattern slots are respectively symmetric with respect to the axis of symmetry. The composite antenna according to claim 8, wherein the plurality of first microstrip metal sheets have a shape of a cross. The composite antenna of claim 9, further comprising: a feed transmission line layer, comprising a plurality of first feed transmission lines and a plurality of second feed transmission lines, each of the first feed transmission lines and each second The feed transmission lines are respectively disposed corresponding to the first microstrip metal piece of the plurality of first microstrip metal pieces, the first feed transmission line and the second feed transmission line being symmetric with the axis of symmetry; and a second dielectric layer, Formed between the feed transmission line layer and the grounded metal plate. The composite antenna of claim 12, wherein the grounded metal plate comprises a plurality of first slots and a plurality of second slots, each of the first slots and each of the second slots respectively corresponding to the plurality of slots a first microstrip metal piece of one of the microstrip metal pieces, the plurality of first slots and the plurality of The second slots are respectively symmetric with the axis of symmetry, and each of the first slots is coupled with the corresponding first feed transmission line, and each of the second slots is coupled with the corresponding second feed transmission line to Increase the bandwidth of the composite antenna. The composite antenna of claim 8, further comprising a second flat dual-polarized antenna layer, the second flat dual-polarized antenna layer comprising a plurality of second microstrip metal pieces, the plurality of second microstrip metal The sheets are respectively formed on the plurality of first microstrip metal sheets and are not in contact with the plurality of first microstrip metal sheets.